Pub Date : 2008-04-22DOI: 10.1109/ICACT.2008.4493908
Zhiquan Bai, D. Yuan, Yingji Zhong, H. Park, K. Kwak
In this paper, a novel code selected M-ary direct sequence ultra wideband communication system is introduced. The objective is to get a high data rate UWB system by using the M-ary coded selected direct sequence bipolar pulse amplitude modulation (MCSDS-BPAM) scheme. In this system, a particular DS code sequence can be selected by the log2(M/2) bits from the DS code set. This scheme can obtain high data rate without increasing the system bandwidth or changing the pulse shape. With the increase of the modulation level M, the system bit error rate (BER) will be improved for the same signal energy per bit. The simulation results are provided in the condition of AWGN channel and correlation receivers.
{"title":"Code Selected M-ary DS-BPAM UWB Communication System","authors":"Zhiquan Bai, D. Yuan, Yingji Zhong, H. Park, K. Kwak","doi":"10.1109/ICACT.2008.4493908","DOIUrl":"https://doi.org/10.1109/ICACT.2008.4493908","url":null,"abstract":"In this paper, a novel code selected M-ary direct sequence ultra wideband communication system is introduced. The objective is to get a high data rate UWB system by using the M-ary coded selected direct sequence bipolar pulse amplitude modulation (MCSDS-BPAM) scheme. In this system, a particular DS code sequence can be selected by the log2(M/2) bits from the DS code set. This scheme can obtain high data rate without increasing the system bandwidth or changing the pulse shape. With the increase of the modulation level M, the system bit error rate (BER) will be improved for the same signal energy per bit. The simulation results are provided in the condition of AWGN channel and correlation receivers.","PeriodicalId":448615,"journal":{"name":"2008 10th International Conference on Advanced Communication Technology","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115372593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-22DOI: 10.1109/ICACT.2008.4494191
S. Haw, Chien-Sing Lee
With the rapid emergence of XML as a data exchange and data transfer medium over the Web, querying XML data has become a major concern. Various optimization technologies, among them those based on XML, have been developed to solve query retrieval problems. In this paper, we suggest an indexing classification scheme and survey the existing path indexing techniques. We also analyze how each approach works, as well as its advantages and disadvantages. In addition, we discuss some of the current trends in indexing methods, which indicate a clear shift towards hybrid approaches. Hybrid systems open the possibility of balancing one technology's weakness with another technology's strengths.
{"title":"Evolution of Structural Path Indexing Techniques in XML Databases: A Survey and Open Discussion","authors":"S. Haw, Chien-Sing Lee","doi":"10.1109/ICACT.2008.4494191","DOIUrl":"https://doi.org/10.1109/ICACT.2008.4494191","url":null,"abstract":"With the rapid emergence of XML as a data exchange and data transfer medium over the Web, querying XML data has become a major concern. Various optimization technologies, among them those based on XML, have been developed to solve query retrieval problems. In this paper, we suggest an indexing classification scheme and survey the existing path indexing techniques. We also analyze how each approach works, as well as its advantages and disadvantages. In addition, we discuss some of the current trends in indexing methods, which indicate a clear shift towards hybrid approaches. Hybrid systems open the possibility of balancing one technology's weakness with another technology's strengths.","PeriodicalId":448615,"journal":{"name":"2008 10th International Conference on Advanced Communication Technology","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123113465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-22DOI: 10.1109/ICACT.2008.4493959
Jin-Young Choi, J. Cho, Seon-Ho Park, Tai M. Chung
Wireless sensors deliver the data to the Base Station which is collected and monitored at the interested environment. To efficiently transmit the data, some nodes are elected to aggregate the data locally and hierarchically. Recently many cluster-based approaches are proposed. In the proposed technologies, UDACH uses a clustering method which considers the energy of each node instead of selecting cluster head randomly like as LEACH. UDACH consists of three stages such as cluster construction, building a cluster head tree and transmitting the data to the base station. The cluster construction is to select cluster node. In the next stage, the cluster heads form tree structure to transmit multi-hop through the parent cluster head. However, if the parent cluster head is not selected appropriately, UDACH dissipates the energy because the total distance of transmission to the BS is longer. In this paper, we propose A Clustering Method of Enhanced Tree Establishment to construct tree structure for the optimized energy consumption. Through the simulation, we describe that the proposed scheme is more effective than LEACH and UDACH routing protocol.
{"title":"A Clustering Method of Enhanced Tree Establishment in Wireless Sensor Networks","authors":"Jin-Young Choi, J. Cho, Seon-Ho Park, Tai M. Chung","doi":"10.1109/ICACT.2008.4493959","DOIUrl":"https://doi.org/10.1109/ICACT.2008.4493959","url":null,"abstract":"Wireless sensors deliver the data to the Base Station which is collected and monitored at the interested environment. To efficiently transmit the data, some nodes are elected to aggregate the data locally and hierarchically. Recently many cluster-based approaches are proposed. In the proposed technologies, UDACH uses a clustering method which considers the energy of each node instead of selecting cluster head randomly like as LEACH. UDACH consists of three stages such as cluster construction, building a cluster head tree and transmitting the data to the base station. The cluster construction is to select cluster node. In the next stage, the cluster heads form tree structure to transmit multi-hop through the parent cluster head. However, if the parent cluster head is not selected appropriately, UDACH dissipates the energy because the total distance of transmission to the BS is longer. In this paper, we propose A Clustering Method of Enhanced Tree Establishment to construct tree structure for the optimized energy consumption. Through the simulation, we describe that the proposed scheme is more effective than LEACH and UDACH routing protocol.","PeriodicalId":448615,"journal":{"name":"2008 10th International Conference on Advanced Communication Technology","volume":"159 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116586522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-22DOI: 10.1109/ICACT.2008.4493807
Y. M. Kim, Guanbo Zheng, Sunghwan Sohn, J. Kim
Cognitive radio is one of the most effective techniques to improve the spectrum utilization efficiency. To implement the cognitive radio, spectrum sensing is considered as the key functionality because secondary users should identify the spectrum holes and utilize them efficiently without causing interference to primary users. In generally, there are three major spectrum sensing methods, including matched filter, energy detection and feature detection. The most common and simplest method is energy detection. However, the conventional energy detection suffers from large degradation in performance under low SNR environment. In this paper, we proposed alternative energy detection which can estimate the exact power of primary user without the noise effect and lead to the better performance. In order to reduce the effect of noise fluctuation, the sliding window function is utilized to assist the proposed detector. The simulation result shows that our proposed method outperform conventional one.
{"title":"An Alternative Energy Detection Using Sliding Window for Cognitive Radio System","authors":"Y. M. Kim, Guanbo Zheng, Sunghwan Sohn, J. Kim","doi":"10.1109/ICACT.2008.4493807","DOIUrl":"https://doi.org/10.1109/ICACT.2008.4493807","url":null,"abstract":"Cognitive radio is one of the most effective techniques to improve the spectrum utilization efficiency. To implement the cognitive radio, spectrum sensing is considered as the key functionality because secondary users should identify the spectrum holes and utilize them efficiently without causing interference to primary users. In generally, there are three major spectrum sensing methods, including matched filter, energy detection and feature detection. The most common and simplest method is energy detection. However, the conventional energy detection suffers from large degradation in performance under low SNR environment. In this paper, we proposed alternative energy detection which can estimate the exact power of primary user without the noise effect and lead to the better performance. In order to reduce the effect of noise fluctuation, the sliding window function is utilized to assist the proposed detector. The simulation result shows that our proposed method outperform conventional one.","PeriodicalId":448615,"journal":{"name":"2008 10th International Conference on Advanced Communication Technology","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127113636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-22DOI: 10.1109/ICACT.2008.4494196
Soo-Cheol Oh, Seongwoon Kim
Cluster systems with high price-to-performance ratio have been utilized in various fields and size of cluster systems is increasing rapidly. Also, as the information retrieval and sharing through the Internet are used widely, scale of portal sites that collect, process and provide information, become larger. These portal sites have large scale cluster system to serve mass information, and operation and maintenance of the large cluster system is a big challenge to the portal sites. Because power cost is one of the main issues in the maintenance of the large cluster system, it is necessary to reduce the power cost of the cluster system. As one solution for this problem, this paper presents the CPU power management mechanism that reduces power usage of the cluster system.
{"title":"Reducing CPU Power Cost of Cluster System","authors":"Soo-Cheol Oh, Seongwoon Kim","doi":"10.1109/ICACT.2008.4494196","DOIUrl":"https://doi.org/10.1109/ICACT.2008.4494196","url":null,"abstract":"Cluster systems with high price-to-performance ratio have been utilized in various fields and size of cluster systems is increasing rapidly. Also, as the information retrieval and sharing through the Internet are used widely, scale of portal sites that collect, process and provide information, become larger. These portal sites have large scale cluster system to serve mass information, and operation and maintenance of the large cluster system is a big challenge to the portal sites. Because power cost is one of the main issues in the maintenance of the large cluster system, it is necessary to reduce the power cost of the cluster system. As one solution for this problem, this paper presents the CPU power management mechanism that reduces power usage of the cluster system.","PeriodicalId":448615,"journal":{"name":"2008 10th International Conference on Advanced Communication Technology","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126719277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-22DOI: 10.1109/ICACT.2008.4494115
Sung-Hoon Kim, Young-hoon Lee, Sung-lk Park, H. Kim, J. Lim, Yong-Seok Kim, Ki-Doo Kim
This paper presents a RTL design of DFE (decision feedback equalizer) for DTxR distributed repeater. Distributed transmission is a key technology of SFN (single frequency network) applied to the ATSC system for terrestrial digital television. DTxR system consist of receiver part, TxID generation & insertion part, and remodulation part. In this paper, we provide a detailed description of pipelined DFE equalizer design for DTxR receiver part, which includes computer simulation results, hardware implementation technology, and Lab test results for DTxR system design and performance evaluation.
{"title":"VLSI Design of DFE Equalizer for ATSC DTxR System","authors":"Sung-Hoon Kim, Young-hoon Lee, Sung-lk Park, H. Kim, J. Lim, Yong-Seok Kim, Ki-Doo Kim","doi":"10.1109/ICACT.2008.4494115","DOIUrl":"https://doi.org/10.1109/ICACT.2008.4494115","url":null,"abstract":"This paper presents a RTL design of DFE (decision feedback equalizer) for DTxR distributed repeater. Distributed transmission is a key technology of SFN (single frequency network) applied to the ATSC system for terrestrial digital television. DTxR system consist of receiver part, TxID generation & insertion part, and remodulation part. In this paper, we provide a detailed description of pipelined DFE equalizer design for DTxR receiver part, which includes computer simulation results, hardware implementation technology, and Lab test results for DTxR system design and performance evaluation.","PeriodicalId":448615,"journal":{"name":"2008 10th International Conference on Advanced Communication Technology","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114922296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-22DOI: 10.1109/ICACT.2008.4493943
Kim Sang-Dong, Jong-hun Lee
This paper analyzes the performance of UWB radar for vehicle in multi-user environments. To evaluate the probability of detection in UWB vehicular radar under a multi-user environment, we use the transmitter and receiver architecture of UWB radar system model. The system model consists of three major parts: a transmitter, multi-path channel and a receiver. Finally, the characteristics of vehicle-mounted UWB radar are evaluated by simulation. Simulation results show that the detection probability is reached with 1 in AWGN channel when relative distance is 120 m and the probability of detection becomes 0.55 when relative distance is 47 m in the IEEE 802.15.4a CM1.
{"title":"Performance analysis of UWB radar for vehicle in multi-user environments","authors":"Kim Sang-Dong, Jong-hun Lee","doi":"10.1109/ICACT.2008.4493943","DOIUrl":"https://doi.org/10.1109/ICACT.2008.4493943","url":null,"abstract":"This paper analyzes the performance of UWB radar for vehicle in multi-user environments. To evaluate the probability of detection in UWB vehicular radar under a multi-user environment, we use the transmitter and receiver architecture of UWB radar system model. The system model consists of three major parts: a transmitter, multi-path channel and a receiver. Finally, the characteristics of vehicle-mounted UWB radar are evaluated by simulation. Simulation results show that the detection probability is reached with 1 in AWGN channel when relative distance is 120 m and the probability of detection becomes 0.55 when relative distance is 47 m in the IEEE 802.15.4a CM1.","PeriodicalId":448615,"journal":{"name":"2008 10th International Conference on Advanced Communication Technology","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114930490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-22DOI: 10.1109/ICACT.2008.4493936
Gunhee Lee, Jaesung Lim, Dong-Kyoo Kim, Sunghyun Yang, Myunghyun Yoon
Various sensors employing ZigBee protocol send environment information to a home gateway. The home gateway manages every devices, sensors and services according to the information. However, if an attacker fabricates the information with malevolent purpose, the system may perform any inadvertent service, which may be harmful to users. Sybil attack is one of serious threats that uses such vulnerability. In this paper, we propose a Sybil attack detection method and its response method to mitigate the effect of the attack in wireless network using ZigBee. The proposed method employs a challenge-response approach. A verifier send a node a request that corresponds to an identity, and the receiver should respond the request properly within threshold time. The performance of the proposed method is reasonable for applying it to the practical networks. This will help the wireless networks using ZigBee to enhance its security.
{"title":"An Approach to Mitigating Sybil Attack in Wireless Networks using ZigBee","authors":"Gunhee Lee, Jaesung Lim, Dong-Kyoo Kim, Sunghyun Yang, Myunghyun Yoon","doi":"10.1109/ICACT.2008.4493936","DOIUrl":"https://doi.org/10.1109/ICACT.2008.4493936","url":null,"abstract":"Various sensors employing ZigBee protocol send environment information to a home gateway. The home gateway manages every devices, sensors and services according to the information. However, if an attacker fabricates the information with malevolent purpose, the system may perform any inadvertent service, which may be harmful to users. Sybil attack is one of serious threats that uses such vulnerability. In this paper, we propose a Sybil attack detection method and its response method to mitigate the effect of the attack in wireless network using ZigBee. The proposed method employs a challenge-response approach. A verifier send a node a request that corresponds to an identity, and the receiver should respond the request properly within threshold time. The performance of the proposed method is reasonable for applying it to the practical networks. This will help the wireless networks using ZigBee to enhance its security.","PeriodicalId":448615,"journal":{"name":"2008 10th International Conference on Advanced Communication Technology","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115086962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-22DOI: 10.1109/ICACT.2008.4494071
Yangjung Kim, Sunghan Song, Dongkyu Lee, I. Chong
Within the NGN architecture, the resource and admission control functions (RACF) act as the arbitrator between service control functions and transport functions for QoS related transport resource control within access and core networks. The decision is based on transport subscription information, SLAs, network policy rules, service priority and transport resource status and utilization information. This paper provides a mechanism for resource control and functional architecture of overlay multicast for IPTV service in NGN.
在NGN架构中，RACF (resource and admission control function)作为业务控制功能和传输功能之间的仲裁器，在接入网和核心网中实现与QoS相关的传输资源控制。决策基于传输订阅信息、sla、网络策略规则、服务优先级以及传输资源状态和利用信息。提出了NGN下IPTV覆盖组播业务的资源控制机制和功能体系结构。
{"title":"A Mechanism for Resource Control and Functional Architecture of Overlay Multicast for IPTV Service in NGN","authors":"Yangjung Kim, Sunghan Song, Dongkyu Lee, I. Chong","doi":"10.1109/ICACT.2008.4494071","DOIUrl":"https://doi.org/10.1109/ICACT.2008.4494071","url":null,"abstract":"Within the NGN architecture, the resource and admission control functions (RACF) act as the arbitrator between service control functions and transport functions for QoS related transport resource control within access and core networks. The decision is based on transport subscription information, SLAs, network policy rules, service priority and transport resource status and utilization information. This paper provides a mechanism for resource control and functional architecture of overlay multicast for IPTV service in NGN.","PeriodicalId":448615,"journal":{"name":"2008 10th International Conference on Advanced Communication Technology","volume":"449 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116022167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-22DOI: 10.1109/ICACT.2008.4493783
Ju Young Kim, J. Kim, Changborm Park
In this work, we propose the methodology for verifying the load limit point of a game server using the large scale virtual clients. It helps to reduce the testing time and to find the load limit point of servers. It explicitly secures the stability of the server for networked virtual environment and at the same time, it elaborately generates actual loads for testing the performance of the server. Our agent based load testing architecture provides variety of interactions of virtual entities in the virtual worlds to perform realistic simulations. Simulation results show that our proposed method ensures the stability and capacity of the servers.
{"title":"Methodology for Verifying the load limit point and bottle-neck of a game server using the large scale virtual clients","authors":"Ju Young Kim, J. Kim, Changborm Park","doi":"10.1109/ICACT.2008.4493783","DOIUrl":"https://doi.org/10.1109/ICACT.2008.4493783","url":null,"abstract":"In this work, we propose the methodology for verifying the load limit point of a game server using the large scale virtual clients. It helps to reduce the testing time and to find the load limit point of servers. It explicitly secures the stability of the server for networked virtual environment and at the same time, it elaborately generates actual loads for testing the performance of the server. Our agent based load testing architecture provides variety of interactions of virtual entities in the virtual worlds to perform realistic simulations. Simulation results show that our proposed method ensures the stability and capacity of the servers.","PeriodicalId":448615,"journal":{"name":"2008 10th International Conference on Advanced Communication Technology","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116071041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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